On this assignment, you are going to test the reliability of a test.

Assignment 2

A reliable instrument is one that is consistent in what it measures.  If an individual scores highly on the first administration of a test, then she or he should score highly on the second administration, if the test is reliable.  On this assignment, you are going to test the reliability of a test.  

Imagine that you are conducting a study for which you developed a content mastery test in math for 8th grade students.  You developed a 30-point test and distributed to 13 students.  The first administration was in April of 2014 and the second administration was in May of 2014.  The scores are listed below.  The correlation coefficient has been provided (correlation coefficient= .90).  Plot each pair of scores on the scatterplot provided below.  What does the information suggest about the reliability of the test?  Explain?   (FYI: Answer can be found in both Chapters 3 and 5).

Scores:

Administration 1           Administration 2 Student 1 17                                 15 Student 2 22                                 18 Student 3 25                                 21 Student 4 12                                15 Student 5 7                                  14 Student 6 28                                27 Student 7 27                                24 Student 8 8                                   5 Student 9 21                               25 Student 10 24                                 21 Student 11 27                                 27 Student 12 21                                 19 Student 13 10                                 15

MATH TEST

Y-Values

Administration 1

Administration 2